<?
$ch = curl_init("http://realivent.com/rss/rss_check?url=".$_GET['url']); 

$sendheaders = array("User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)",);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_HEADER, 0); // set to 0 to eliminate header info from response
curl_setopt($ch, CURLOPT_NOBODY, 0); // set to 1 to eliminate body info from response
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0); // use HTTP/1.0 instead of 1.1
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // Returns response data instead of TRUE(1)
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); // uncomment this line if you get no gateway response. ###
curl_setopt($ch, CURLOPT_HTTPHEADER, $sendheaders);
//curl_setopt($ch, CURLOPT_POSTFIELDS, $fields); // use HTTP POST to send form data

$resp = curl_exec($ch); //execute post and get results
curl_close ($ch); 

if(substr($resp,12,7)!='Warning')
{
echo 'This feed appears to be valid, go ahead and submit it.';
}
else
{
echo 'This is not a valid feed. Please check the url. The most common error is that users try to add their website url and not their feed url. For example, if your website url is www.domain.com, your feed url is probably www.domain.com/feed.';
}
?>